For any of the activities regulated by this chapter, the preliminary or final approval of subdivision and/or land development plans, the issuance of any building or occupancy permit, or the commencement of any earth disturbance activity may not proceed until the property owner or applicant or his/her agent has received written approval of a drainage plan from the municipality, obtained an NPDES permit for stormwater discharges associated with construction activities, if greater than one acre of land disturbance, from the Montgomery County Conservation District and/or DEP, and an adequate erosion and sediment control plan review by the Conservation District. The Borough shall be provided with a copy of all outside agency permit applications and final approval or permit.
The drainage plan shall consist of a general description of the project, including sequencing items described in § 101-19, calculations, maps, and plans. A note on the maps shall refer to the associated computations and erosion and sediment control plan by title and date. The cover sheet of the computations, erosion and sediment control plan, and post-construction stormwater management (PCSM) plan shall refer to the associated maps by title and date. All drainage plan materials shall be submitted to the municipality in a format that is clear, concise, legible, neat, and well organized. If not, the drainage plan shall not be accepted for review and shall be returned to the applicant. The following items shall be included in the drainage plan:
A. 
General.
(1) 
General description of the project, including those areas described in § 101-19B.
(2) 
General description of proposed permanent stormwater management techniques, including construction specifications of the materials to be used for stormwater management facilities.
(3) 
Complete hydrologic, hydraulic, and structural computations for all stormwater management facilities.
(4) 
An erosion and sediment control plan, including all reviews and letters of adequacy from the Conservation District, as applicable.
(5) 
A general description of proposed nonpoint source pollution controls.
(6) 
The drainage plan application (Appendix B).[1]
[1]
Editor's Note: Said appendix is on file in the Borough offices.
(7) 
The development or construction schedule.
B. 
Maps. Map(s) of the project area shall be submitted on twenty-four-inch-by-thirty-six-inch sheets and/or shall be prepared in a form that meets the requirements for recording at the offices of the Recorder of Deeds of Montgomery County. If the SALDO has more stringent criteria than this chapter, then the more stringent criteria shall apply.[2] The contents of the map(s) shall include, but not be limited to:
(1) 
The location of the project relative to highways, municipal boundaries, or other identifiable landmarks.
(2) 
Existing contours at intervals of two feet. In areas of slopes greater than 25%, five-foot contour intervals may be used.
(3) 
Existing streams, lakes, ponds, or other waters of the commonwealth within the project area.
(4) 
Other physical features, including flood hazard boundaries, stream buffers, existing drainage courses, areas of natural vegetation to be preserved, and the total extent of the upstream area draining through the site.
(5) 
The locations of all existing and proposed utilities, sanitary sewers, and waterlines within 50 feet of property lines.
(6) 
An overlay showing soil names, boundaries and limitations (in tabular format).
(7) 
Limits of earth disturbance, including the type and amount of impervious area that would be added.
(8) 
Proposed structures, roads, paved areas, and buildings.
(9) 
Final contours at intervals of two feet. In areas of steep slopes (greater than 25%), five-foot contour intervals may be used.
(10) 
The name of the development, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.
(11) 
The date of submission.
(12) 
A graphic and written scale of one inch equals no more than 50 feet; for tracts of 20 acres or more, the scale shall be one inch equals no more than 100 feet.
(13) 
A North arrow.
(14) 
The total tract boundary and size, with distances marked to the nearest foot and bearings to the nearest degree.
(15) 
Existing and proposed land use(s).
(16) 
A Key Map showing all existing man-made features beyond the property boundary that would be affected by the project.
(17) 
The location of all open channels, as well as indicating where they are draining after they leave the site (storm sewer, defined drainage swale, stream channel, waters of the commonwealth, etc.).
(18) 
Overland drainage patterns and swales.
(19) 
A fifteen-foot-wide access easement to all stormwater management facilities that would provide ingress to and egress from a public right-of-way.
(20) 
The location of all erosion and sediment control facilities, both temporary and permanent, and all post-construction stormwater management facilities, BMPs, systems, etc.
(21) 
A statement, signed by the applicant, acknowledging that any revision to the approved plan must be approved by the municipality. If more than one acre of land is disturbed, the Conservation District and/or DEP must approve the plan. Any revision to the erosion and sediment control plan must be submitted to the approving agency for a determination of adequacy.
(22) 
The following signature block for the design engineer: "I, (Design Engineer), on (date of signature), hereby certify that the drainage plan meets all design standards and criteria of the West Conshohocken Borough Stormwater Management Ordinance."
[2]
Editor's Note: See Ch. 102, Subdivision and Land Development.
C. 
Supplemental information to be submitted to the municipality.
(1) 
A written description of the following information shall be submitted by the applicant and shall include:
(a) 
The overall stormwater management concept for the project designed in accordance with § 101-19.
(b) 
Stormwater runoff computations as specified in this chapter.
(c) 
Stormwater management techniques to be applied both during and after development.
(d) 
Expected project time schedule.
(e) 
Development stages or project phases, if so proposed.
(f) 
An operations and maintenance plan in accordance with § 101-30 of this chapter.
(2) 
An erosion and sediment control plan.
(3) 
A description of the effect of the project (in terms of runoff volumes and peak flows) on adjacent properties and on any existing municipal stormwater collection system that may receive runoff from the project site.
(4) 
A declaration of adequacy and a highway occupancy permit from the Pennsylvania Department of Transportation (PennDOT) district office when utilization of a PennDOT storm drainage system is proposed.
D. 
Stormwater management facilities.
(1) 
All PCSM BMP facilities must be located on a plan and described in detail. The PCSM plan package should include, at a minimum, pre- and post-drainage area plans, an overall PCSM plan, PCSM details sheets, landscaping or conservation plans, etc.
(2) 
When infiltration measures, such as seepage pits, beds, or trenches, are used, the locations of existing and proposed septic tanks, infiltration areas and wells must be shown. Minimum setback distances should be identified from water supply wells, septic areas, and any adjacent or downgradient buildings and/or structures with below-grade floors or inhabitable space. This shall be done on the proposed development site and/or downgradient of the site.
(3) 
All calculations, assumptions, and criteria used in the design of the stormwater management facilities must be shown.
The municipality shall require a complete drainage plan, as specified in this chapter.
A. 
Proof of application or documentation of required permit(s) or approvals for the permits listed below shall be part of the plan:
(1) 
NPDES permit for stormwater discharges from construction activities.
(2) 
DEP joint permit application.
(3) 
PennDOT highway occupancy permit and/or West Conshohocken Borough road opening permit, as applicable.
(4) 
Chapter 105 (Dam Safety and Waterway Management).[1]
[1]
Editor's Note: See 25 Pa. Code Chapter 105.
(5) 
Chapter 106 (Identified Floodplain Area Management).[2]
[2]
Editor's Note: See 25 Pa. Code Chapter 106.
(6) 
Any other permit under applicable state or federal regulations.
B. 
The plan shall be coordinated with the state and federal permit process and the municipal SALDO review process.[3]
[3]
Editor's Note: See Ch. 102, Subdivision and Land Development.
C. 
For projects that require SALDO approval, the drainage plan shall be submitted by the applicant as part of the preliminary plan submission where applicable for the regulated activity.
D. 
For regulated activities that do not require SALDO approval, see § 101-10, General requirements.
E. 
Six copies of the drainage plan may be submitted to the Borough and distributed as follows:
(1) 
Two copies to the municipality accompanied by the requisite municipal review fee, as specified in this chapter.
(2) 
Two copies to the County Conservation District.
(3) 
One copy to the Municipal Engineer.
(4) 
One copy to the County Planning Commission/Department.
F. 
Any submissions to the agencies listed above that are found to be incomplete shall not be accepted for review and shall be returned to the applicant with a notification in writing of the specific manner in which the submission is incomplete.
A. 
The Municipal Engineer shall review the drainage plan for consistency with this chapter, the West Conshohocken Borough Stormwater Management Ordinance. Any plans found incomplete shall not be accepted for review and shall be returned to the applicant.
B. 
The Municipal Engineer shall review the drainage plan for any subdivision or land development against the Municipal SALDO provisions not otherwise superseded by this chapter.[1]
[1]
Editor's Note: See Ch. 102, Subdivision and Land Development.
C. 
The Conservation District, in accordance with established criteria and procedures, shall review the drainage plan for consistency with stormwater management and erosion and sediment pollution control requirements and provide comments to the municipality. Such comments shall be considered by the municipality prior to final approval of the drainage plan.
D. 
For activities regulated by this chapter, the Municipal Engineer shall notify the applicant and the municipality in writing, within 30 calendar days, whether the drainage plan is consistent with this chapter.
(1) 
If the Municipal Engineer determines that the drainage plan is consistent with this chapter, the Municipal Engineer shall forward a letter of consistency to the applicant.
(2) 
If the Municipal Engineer determines that the drainage plan is inconsistent or noncompliant with this chapter, the Municipal Engineer shall forward a letter to the applicant citing the reason(s) and specific ordinance sections for the inconsistency or noncompliance. Inconsistency or noncompliance may be due to inadequate information to make a reasonable judgment as to compliance with this chapter. Any drainage plans that are inconsistent or noncompliant may be revised by the applicant and resubmitted. The applicant shall be notified of the Municipal Engineer's findings.
E. 
For regulated activities specified in § 101-5 of this chapter that require a building permit, the Municipal Engineer shall notify the Municipal Building Code Official in writing, within a time frame consistent with the Municipal Building Code and/or Municipal SALDO, whether the drainage plan is consistent with the Stormwater Management Ordinance. The Municipal Building Code Official shall forward a copy of the consistency/inconsistency letter to the applicant. Any drainage plan deemed inconsistent may be revised by the applicant and resubmitted.
F. 
For regulated activities under this chapter that require an NPDES permit, the applicant shall forward a copy of the Municipal Engineer's letter stating that the drainage plan is consistent with this chapter to the Conservation District and/or DEP. In addition, a short summary of the proposed post-construction stormwater management design and proposed BMPs should also be forwarded to the Conservation District and/or DEP. DEP and the Conservation District may consider the Municipal Engineer's review comments in determining whether to issue a permit.
G. 
The municipality shall not grant preliminary or final approval to any subdivision or land development for regulated activities specified in § 101-5 of this chapter if the drainage plan has been found by the Municipal Engineer to be inconsistent with this chapter. All required permits from DEP must be obtained prior to approval of any subdivision or land development.
H. 
No building permits for any regulated activity specified in § 101-5 of this chapter shall be approved by the municipality if the drainage plan has been found to be inconsistent with this chapter, as determined by the Municipal Engineer and/or the Conservation District, or without considering the comments of the Municipal Engineer and/or the Conservation District. All required permits from DEP must be obtained prior to issuance of a building permit.
I. 
The applicant shall be responsible for completing record drawings of all stormwater management facilities included in the approved drainage plan at the end of the project. The record drawings and an explanation of any discrepancies with the design plans shall be submitted to the Municipal Engineer for final approval. In no case shall the municipality approve the record drawings until the municipality receives a copy of an approved declaration of adequacy and/or highway occupancy permit from the PennDOT District Office, NPDES permit, and any other applicable permits or approvals from DEP or the Conservation District. The above permits and approvals must be based on the record drawings.
J. 
The municipality's approval of a drainage plan shall be valid for a period not to exceed five years commencing on the date that the municipality signs the approved drainage plan. If stormwater management facilities included in the approved drainage plan have not been constructed or, if constructed, record drawings of these facilities have not been approved within this five-year time period, then the municipality may consider the drainage plan inconsistent or noncompliant and may revoke any and all permits. Drainage plans that are determined to be inconsistent or noncompliant by the municipality shall be resubmitted in accordance with § 101-15 of this chapter.
A. 
A modification to a submitted drainage plan under review by the municipality for a development site that involves the following shall require a resubmission to the municipality of a modified drainage plan consistent with § 101-12 of this chapter and be subject to review as specified in § 101-13 of this chapter:
(1) 
Change in stormwater management facilities or techniques;
(2) 
Relocation or redesign of stormwater management facilities; or
(3) 
Is necessary because soil or other conditions are not as stated on the drainage plan as determined by the Municipal Engineer.
B. 
A modification to an already approved or inconsistent or noncompliant drainage plan shall be submitted to the municipality, accompanied by the applicable municipal review and inspection fee. A modification to a drainage plan for which a formal action has not been taken by the municipality shall be submitted to the municipality accompanied by the applicable municipal review and inspection fee.
An inconsistent or noncompliant drainage plan may be resubmitted with the revisions addressing the Municipal Engineer's concerns documented in writing. It must be addressed to the Borough in accordance with § 101-12 of this chapter, distributed accordingly, and be subject to review as specified in § 101-13 of this chapter. The applicable municipal review and inspection fee must accompany a resubmission of an inconsistent or noncompliant drainage plan.